Diamond Drill

Diamond Drill300 GRAM in game (≈30,000 CROWN at the presale rate), 150 GRAM in the presale

Adds +300 mining power. The power of every drill you own adds up, so a new drill does not replace the old one, it stacks on top.

Shards per hour from this drill = 300 × 300 × buildings × boosts × depth

At current competition that is about 1944.81 CROWN per day, paying back in roughly 15.40 days.